| Author |
Message |
    
Mark Tomlinson
Frequent User
Username: mark_tomlinson
Post Number: 22
Registered: 9-2003
| | Posted on Tuesday, 24 August, 2004 - 09:46 pm: |    |
I am becoming frustrated at the lack of power my 71 stretched shadow has and although I have asked in the past would turbo charging be an option the responses were the diff would not handle it and the cost would be too great.
I have recently fitted electronic ignition to some degree of satisfaction but am now wondering if supercharging is an option or at least flow the heads and put heavier valve springs with a cam to suit as this did wonders for my long stroke Harley.
Any advise on making this dinosaur more powerful would be a help.
Thank you. |
Robert Chapman
Prolific User
Username: shadow
Post Number: 67
Registered: 5-2003
| | Posted on Wednesday, 25 August, 2004 - 08:02 am: | |
Mark,
I think you would have to be carefull with a supercharger or a cam as both would increase the dynamic compession ratio and you could face problems with deternation on the fuel available.
Might pay to pull out a plug and have a look inside the cylinder to see what compression engine you have to start with.
All this presumes your engine is in good tune now and has no mechanical faults effecting output. |
Pat Lockyer.
Unregistered guest
Posted From: 81.131.90.224
| | Posted on Wednesday, 25 August, 2004 - 08:38 am: | |
Mark this is a long shot but the Shadows that i deal with go like the clappers high or low compression through the gears,could well be a duff torque converter? |
Mark Tomlinson
Frequent User
Username: mark_tomlinson
Post Number: 23
Registered: 9-2003
| | Posted on Wednesday, 25 August, 2004 - 07:13 pm: | |
Robert,I have been advised that I have a 9:1 compression ratio engine and a supercharger is not the way to go, I am still waiting for the jury on the cam and so forth. |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 325
Registered: 4-2003
| | Posted on Wednesday, 25 August, 2004 - 08:32 pm: | |
As Pat pointed out, a broken torque converter will give you as little as 1/3 torque at less tha 3,000 rpm. A duff converter is usually silent, and the only symptom is poor acceleration.
The sprag clutch on the converter stator can fail, leading to this. You may not notice when it fails. The transmission will probably overheat as a result. Sometimes the engine cooling system can overheat as it gets rid of the wasted energy from the converter, especially if you have the radiator transmission heat exchanger. However, your car should have the in-line exchanger beneath the transmission which is less effective.
My converter sprag gave way a few months ago, so I replaced the converter successfully. I was puzzled at first, thinking that the Turbo had collapsed. It was like the car had suddenly lost all its power.
9:1 Shadows have bags of power. None were faster until the Turbo Bentleys arrived.
See the schrapnel I retrieved from my converter ! It was once the stator sprag clutch.
 |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 326
Registered: 4-2003
| | Posted on Wednesday, 25 August, 2004 - 09:04 pm: | |
PS changing a Crewe V8 camshaft is a really rotten job to do. A changed profile will not give you much extra torque (probably even less) where you need it low down. I have been successful with a high lift, long duration cam on my R-Type, but would would never attempt it on a Crewe V8. |
John Dare
Unregistered guest
Posted From: 144.138.194.43
| | Posted on Thursday, 26 August, 2004 - 06:48 am: | |
Well years ago we had the REAL induction "assisted" cars with the "Blower" Bentleys. Given that "Holden" (GM) "Mercedes" (der Kompressor,ya!) Jaguar (XJ8) and even the "Mini" are now in on the act, maybe a suitable supercharger might be worth looking at for a Shadow etc., rather than turbochargers which are somewhat passe. Need to think about compression ratios, but I know my professional mechanic will be able to suitably enlighten me in that regard |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 327
Registered: 4-2003
| | Posted on Thursday, 26 August, 2004 - 08:22 am: | |
By the way, Mark. As a DaimlerChrysler engineer until last year, I can hint that the recent dabble with superchargers was a disaster not to be repeated. |
David Gore
Moderator
Username: david_gore
Post Number: 280
Registered: 4-2003
| | Posted on Thursday, 26 August, 2004 - 10:57 am: | |
Hi Mark,
One option you should consider would be to install a dual exhaust system similar to the later Shadows or just upgrade from the standard 2 inch exhaust to 2.25 inch as on the Corniche - the reduction in back pressure will improve engine breathing however you will need to spend some time with an exhaust gas analyser and "colourtune" spark plug to fine-tune the mixture - my choice would be the dual exhaust with a balance pipe between each side to give a better exhaust note and improve gas flow. |
William H. Trovinger II
Grand Master
Username: bill_trovinger
Post Number: 150
Registered: 8-2003
| | Posted on Thursday, 26 August, 2004 - 01:04 pm: | |
Richard;
Please tell me that you had nothing to do with wife's 2000 C230K that had to be taken back under lemon law? 
Regards,
Bill |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 330
Registered: 4-2003
| | Posted on Thursday, 26 August, 2004 - 07:24 pm: | |
Bill T,
Nothing directly to do with me. Needless to say, the supercharged Kompressor cars are being quietly dropped. |
John Dare
Unregistered guest
Posted From: 144.138.194.24
| | Posted on Friday, 27 August, 2004 - 07:38 am: | |
Maybe there was something "kaput" mit der Kompressors?. If not, lets hope small time players like GM(supercharged "Holden") Ford (Premier Auto Group)with their "Jaguar" XJ8 and the GERMAN BMW "Mini", DONT hear from about this or THEY too might feel "obliged" to revisit THEIR disasters(??) too!. No such worries or problems for me though with an Eaton M90 on my Range Rover. 930 Turbo performance in a Rolls-Royce kit; wood/elec.seats (Connolly of course!)self level. suspension (Look Ma .. No OIL ..its..its.. AIR!!!). EFI Turbos etc., out of my way,please. |
Mark Peacock
Frequent User
Username: takemehomejames
Post Number: 18
Registered: 4-2004
| | Posted on Monday, 30 August, 2004 - 09:28 pm: | |
Mark,
Im quietly working on a "kit" to supercharge a Shadow.
Kit one utilising the later mulsanne turbo 4 barrel manifold, &
kit 2 using a manifold that im designing to run using EFI (8 Injectors)with seperate fuel/ign computer . Combined with a reprofiled cam, roller rockers,flowed heads,and the tricky part... modified headers. Combining the best of no lag, plenty of torque and quiet performance with a hint of belt noise...
And in regards to the turbo R having less flex than a shadow. yes it was done with i think was done with a few more spot welds here and there.
It only leaves the flimsy torque arm.. which i replaced long ago with a fabricated aluminium unit , which is stronger than the spirit type.
|
John Dare
Unregistered guest
Posted From: 144.138.195.31
| | Posted on Monday, 30 August, 2004 - 10:37 pm: | |
Sounds exciting Mark, but you might need to consider the location of the supercharger, as I too, have been considering such a project for a while now. As there is marginal clearance under the bonnet/hood, you might need to consider a slight bonnet "bulge" of sorts, but (hopefully) any worthwhile alum.fabricator ought to be able to do this without it being too obvious. I had considered trialling an "Eaton" unit on a Bentley "T" which I might be buying soon, as the Bentley bonnet/grille might (possibly) be more visually receptive to a subtle bulge as opposed to the Shadow with its more defined angles etc. Besides, REAL Bentleys were of course supercharged, werent they?. In any event, FORGET the basic ABC "mechanical" compression ratio/s and consider the reality of the varying and increased DYNAMIC ratio, since thats the (real) ratio that counts with the attendant V/E. Doubtless you will be IMpressed as "more" is COMpressed!.Please keep us posted as you proceed. |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 334
Registered: 4-2003
| | Posted on Tuesday, 31 August, 2004 - 03:24 am: | |
Mark P.
Just for the record and not to score points in any way, have a look at the diagram below. The upper drawing is that of a Silver Shadow series torque arm. The weak point is near the fingers at the chassis end (right hand side of the diagram) where the arm flexes and fatigues.
The other is an SZ series torque arm. It is essentially a substantial flat plate with all the forces in shear. It is intrinsically far more robust than the Shadow type and is virtually indestructible. Failure is more or less impossible as the fundamental design, with no flex point at all, is so much more sensible.
I don't really believe that any Shadow replacement can be stronger than the SZ type. However, failure of the later type Shadow torque arm does not occur, so who cares ?
RT.
 |
Mark Peacock
Frequent User
Username: takemehomejames
Post Number: 20
Registered: 4-2004
| | Posted on Tuesday, 31 August, 2004 - 06:40 am: | |
Totally agree. I was making mention to the body shell in regards to the extra stiffness. The sz torque arm is exactly what ive made.. No more dramas. |
John Dare
Unregistered guest
Posted From: 144.138.194.220
| | Posted on Tuesday, 31 August, 2004 - 07:55 am: | |
A friend in the USA fitted a large (approx.6L) US V8 into his Shadow and a retired aircraft (airFRAME) mechanic friend, built ( I THINK from aluminium) "aero" type (lots of "holes"!)final drive members/torque arms etc., but even THEY too EVENTUALLY developed cracks . He was reluctant to increase their rigidity as he noted that such driveline components need to have some degree of flex in them, otherwise forces are referred to unintended locations elsewhere within the body structure. Although I am neither structural engineer or overall "expert" on anything and everything, I do have an laymans awareness of what the practical "problem/s" appear to be in this area. I need to consider this is the T1 project. |
David Gore
Moderator
Username: david_gore
Post Number: 291
Registered: 4-2003
| | Posted on Tuesday, 31 August, 2004 - 11:47 am: | |
To solve the concerns - from a fatigue resistance perspective, controlled flex is necessary to avoid the stress concentrations that cause cracking.
I suspect the SZ member relies on movement in the resilient mounts between the member and the body to provide the necessary flex to avoid cracking. As a humble metallurgist, the SZ design represents good practice. |